Press for the production of artistic prints and impressions



J. GRUNBERG Dec. 117, 1929.

PRESS FOR THE PRODUCTION OF ARTISTIC PRINTS AND IMPRESSIONS Filed Sept.21, 1927 lf/i Patented Dec. 17, 1929 ATNT QFFIQE JOSEF GRTJ'NBERG, OFBERLIN, GERMANY PRESS FOR THE PRODUCTION OF ARTISTIC PRINTS ANDIMPRESSIONS Application filed September 21, 1927, Serial N0. 221,065,and in Germany September 24, 1926.

My United States Patent 1,547,8Z1 relates to a press for the productionof artistic prints and impressions. The material to be printed etc., vizpaper or the like, is subjected to pres- 5 sure by means of an elasticwall of a pressure receptacle by which it is pressed onto the originalblock or matrix. It has, however, been discovered that it is connectedwith difficulties to pack and tighten the inserted elastic wall withrespect to the atmosphere on account of the high pressure existing insaid pressure receptacle. Thisis true, in fact, of all joints of thepress, and to judge correctly upon the importance of the matter it mustbe 5 considered that if only a trace of the liquid substance used, viz,preferably oil, escapes valuable prints may be rendered useless.

The object of the present invention is to do away with that gravedrawback, and for this purpose I now make use of an elastic wallconstituted by a plate consisting of a yielding material and having aflange which acts as packing and tightening means under the action ofthe pressure existing in the pressure receptacle. The flanged rim of theyielding plate is, preferably, so high that it extends from the bottomto the top of the pressure space and covers, therefore, all joints.

In my above-mentioned previous United States patent-the abutment for theoriginal block, viz the printing table, is formed in particular cases byan elastic wall of a pressure receptacle, and in order to hold that walltightly upon its seat the rim of the same is subjected, during theprinting procedure, to the pressure of the upper elastic wall, the rimportion of which, therefore, can no more act as pressing surface. Thisis obviously another drawback, but also this drawback is overcome in mypresent improved press. In this latter also the abutment is formed by aplate consisting of a yielding material and having a flanged packing ortightening rim. The packing and tightening procedure is effecteddirectly by the flanged rim, and the elastic surface acting during theprinting procedure needs no more to act as a means for packing andtightening the abutment surface.

When the flanged rim of the elastic printing surface, or of abutmentsurface, extends from the bottom to the top of the pressure space and,therefore, covers the side walls of the same, porous places existing,perhaps, in the walls of the pressure receptacle are insigv niticant, asthe pressing medium does not contact directly with said walls, and inorder to prevent the liquid under pressure from contacting directly withthe walls of the press the surfaces of the upper and the lower liquidspace can be provided with a covering of a material impervious to thefluid or liquid under pressure, for instance rubber. This covering maybe formed by a hood forming, together with the elastic wall of the upperor the lower liquid space, a closed pressure space.

The invention is illustrated diagrammatically and by way of example onthe accompanying drawing on which is shown a vertical section through aprinting press designed according to this invention.

On the drawing, 1 denotes the frame of the press and 2 an insertedcover, the lower part of which is concavo-conveX and forms below 7 it anopen space 3. This space is closed from below by a hollow elastic body4, the wall 4 of which is flanged at its upper edge, the flange 4contacting with the rim of the bottom part of the cover 2, the upperpart of 80, which is firmly connected with the frame or body of thepress by screws or bolts (not shown). The member 4 may consist of rubheror the like. When the liquid under pressure, for instance an oil, isintroduced into the space 3 and the member 4 through a pipe 5, all partsof this member, except the centre part, are pressed against theneighbouring rigid walls, whereby perfect tightness is obtained.

In the lower part of frame 1, below the member 4, a car 7, forming theprinting-table, is movable on rails 6. The car is hollow and forms aspace 3 also enclosing an elastic member 8 closing the space of the carand forming a chamber. Also this member consists preferably of rubber,and its side wall 8 has a flange 8 the whole being practically aninverted member l, 4 4 except the thick centre portion of the member 4:.If pressure is produced in the chamber 3 the sides and the flange of themember 8 are pressed against the neighbouring rigid walls, just as withthe member 4:, whereby the member 8 is tightened. The upper, horizontal,flat part of the member 8 supports the original piece together with thematerial to be printed or to be impressed, viz paper, paste-board, metalfoil or the like. By lifting the car 7 for instance in the mannerdescribed in my aforesaid patent specification, the material to beprinted or to be impressed is moved towards the elastic wall 4:. Now thefluid or liquid under pressure is pressed into the chamber 3, i. e. thespace enclosed between the members 2 and 4, whereby the printing orimpressing is elfected.

The bottom surface of the cover 2 and the inner bottom surface of theprinting table 7, are provided, in the example shown, with coverings 9and 9 consisting of a material, for instance rubber, impervious to thefluid or liquid under pressure. The upper capshaped covering 9 and thelower basin-shaped covering 9 have each a flanged rim 9 and 9respectively, and each is inserted loosely into the respective cavitywhere it is held in place by the flange 4: or 8 respectively. It is, however, also possible to connect the contacting flange-s by vulcanization.In every case the members l and 9 in the upper part of the press and themembers 8 and 9 in the lower part of the same form closed chambers. Thecovering 9 is preferably provided with tubular extensions 9 as shown,the object of which is obvious.

I claim:

1. A printing press of the kind described, comprising in combination, apressure receptacle open at one side, an elastic wall loosely insertedin said receptacle and arranged to close the open side of saidreceptacle, said elastic wall having an inwardly bent rim, arranged tolie close to the inner walls of said pressure receptacle and adapted totighten up said receptacle when the pressure is increased within thelatter.

2. A printing press of the kind described, comprising in combination, apressure receptacle open at one side, an elastic wall loosely insertedin said receptacle and arranged to close the open side of saidreceptacle, said elastic wall having an inwardly bent rim and extendingfrom the bottom of said pressure receptacle to the top of the same, saidrim being arranged to lie close to the inner rigid walls of saidpressure receptacle and adapted to tighten up said receptacle when underpressure.

3. A printing press of the kind described, comprising in combination, apressure receptacle open at one side, an elastic wall loosely insertedin said receptacle and arranged to close the open side of saidreceptacle, said elastic wall having an inwardly bent rim and signature.

J OSEF GRUN BERG.

